1. Field of the Invention
The invention relates to hand held tool that can be used by a carpenter or other tradesman to perform a plurality of critical tasks easily.
2. Description of the Related Art
Carpenters require convenient access to a plurality of tools for performing each of a plurality of different functions. As a result, most carpenters wear a tool belt and/or remain close to a box, bucket or bag that contains the tools the carpenter is likely to need during the course of a day. Drywall installation represents a substantial amount of the work done by many carpenters and is a task that many home improvement enthusiasts will attempt.
Drywalls are formed from planar sheets of gypsum board. In particular, a gypsum slurry is formed into a substantially planar shape and secured between two sheets of a fairly sturdy paper. One sheet of paper is more finished than the other and defines the front finished surface of a gypsum board. The gypsum board comes in varying thicknesses from ⅜ inch.
Gypsum board typically is cut by marking a straight line on the finished surface of the gypsum board and then cutting into the gypsum board using a razor sharp utility knife. The cut passes through the paper on the finished side of the gypsum board and partly into the gypsum. The severance of the paper substantially weakens the gypsum board. The carpenter then exerts pressure on the finished side of the gypsum board on either side of the cut. As a result, the gypsum board breaks fairly cleanly along the cut, but remains attached by the paper on the rear surface of the gypsum board. The carpenter then utilizes the razor sharp utility knife to cut through the paper on the rear surface of the gypsum board.
The cut sections of the gypsum board closely match the initial dimensions marked by the carpenter. Additionally, the cut edge typically will be quite smooth adjacent the finished surface of the gypsum board. However, the cut edge will be less smooth at areas closer to the rear surface of the gypsum board due to the breaking of the gypsum material as the gypsum board is folded at the cut. A rough edge may not be a problem in many installation sites, but can be a problem at other locations. In these situations, the carpenter will smooth out the rough edge at the cut. The smoothing typically is carried out with a gypsum board rasp that generally resembles the rough surface of a cheese grater. The rasp also may be employed to make the cut sheet of gypsum board smaller if the initial measurement was inaccurate. In this regard, it is difficult to perform the above-referenced cutting and bending procedure to remove a small sliver of gypsum board (e.g. 0.25 inch–0.50 inch). However, these relatively thin slivers can be removed rather easily with the rasp.
The razor sharp utility knives used by most carpenters can cause very serious cuts. As a result, many utility knives have a retractable blade. The blades dull quite easily during normal usage and must be replaced frequently. Most utility knives have a handle with two opposed halves that are secured together. The halves must be separated to remove a used blade. A new blade then is positioned between the halves of the utility knife and the two halves are secured together again.
The appropriately cut sheet of gypsum board typically is mounted to a wall or ceiling. More particularly, the unfinished rear side of the gypsum board is positioned against the studs, and drywall screws are used to secure the gypsum board to the studs. However, gypsum board must be adapted to accommodate electrical outlets, lighting switches, telephone jacks and heating or air conditioning ducts. The openings required for these utilities often are not at the periphery of the sheet of gypsum board, and hence are not readily cut by the above-described procedure employing the razor sharp utility knife. Accordingly, a carpenter will employ a keyhole saw. A keyhole saw is tapered to a well defined point and has a fairly rough array of teeth along an edge of the saw. The carpenter urges the sharp point of the keyhole saw into and through the gypsum board. The carpenter then uses a reciprocal motion to cut through the gypsum board. The edges cut by a typical keyhole saw will be fairly jagged and may require trimming by the above-mentioned rasp. The typical keyhole saw has a blade about six inches long and a rigid substantially cylindrical handle projecting longitudinally from the blade. This typical shape makes the keyhole saw easy to use. However, the same shape complicates storage and handling between uses. In particular, the keyhole saw is not easily stored or carried on a carpenters belt and can be dangerous when stored in a tool box, bucket or bag.
A drill typically is used to mount drywall screws into the gypsum board. Carpenters generally can locate the studs accurately. However, even an experienced carpenter will periodically miss a stud. In this situation the head of the screw quickly advances into a position substantially flush with the surface of the gypsum board. A screw that is mounted in a stud can be removed easily merely by reversing the drill. However, the threads of a screw that has missed the stud are not engaged with anything. Thus, a reversal of the drill causes the screw to rotate in place, but does not retract the screw from the wall. In this situation, the carpenter must retreat to the tool box to obtain still another tool that can be urged under the head of the screw to bias the screw away from the wall while the drill is being rotated in the reverse direction. A small screwdriver often is used for this purpose. However, the pointed end of the screw driver does not achieve the leverage action for removing the screw. Most pry bars used by carpenters are much too big for this purpose. Hence, the seemingly easy task of removing a screw that has missed a stud can be annoying and time consuming.
The screw holes in the gypsum board and the seams between adjacent sheets of gypsum board are covered with a joint compound. The joint compound is a paste-like material that hardens to a consistency similar to the cured gypsum board. Joint compound, however, generally is not preferred for sealing around windows or doors. Additionally, joint compound often will crack when used at the interface between two surfaces with different expansion and contraction characteristics, such as a joint between gypsum board and wood molding. A more pliable silicone sealant or construction adhesive typically will be used at these locations. Additionally some sheets of wallboard are adhered to a wall rather than using screws. Adhesives and silicone sealants are sold in paperboard or plastic tubes with a pointed plastic nozzle. The tube is sealed by a thin foil membrane and the nozzle initially is tapered to a closed point. The carpenter installs the tube into a caulking gun. The above-described razor sharp utility knife then is used to cut off the tip of the plastic nozzle. A long thin pointed implement then is passed into the cut nozzle sufficiently to puncture the foil so that the adhesive or silicone sealant can be urged from the tube by the caulking gun. Most tools maintained by a carpenter are not well suited to the task of puncturing the foil membrane on a tube of adhesive or silicone sealant. Thus, many carpenters will use a long nail for this purpose.
The tasks described above require frequent access to many different tools including the razor sharp utility knife, the keyhole saw, the rasp, one or more tools to facilitate the removal of screws that have missed a stud and a tool to puncture the foil seal on a tube of silicone sealant. Thus, carpenters spend considerable time looking for and accessing the tools that are required to complete their day-to-day tasks. Many of these tools are not well suited to being suspended on a belt. Additionally, many of these tools are sufficiently sharp to cause cuts or abrasions on the hand. Accordingly, the attempts to access these tools can be dangerous. The likelihood of cuts or scrapes is particularly high in view of the frequency at which these tools are accessed and the preference of workers to complete their tasks as quickly as possible.
Combination tools have been developed for many purposes. These tools often take the form of a conventional pocket knife where implements such as knives, forks, can openers and screwdrivers can be folded into and out of a handle. The available combination tools are not well suited to the many functions that must be carried out by carpenter, as described above. Rather, most combination tools of this type are used more in a recreational context by campers or as part of key chain. The existing combination tools are not adapted for the frequent changing of utility knife blades or the easy retraction of the razor sharp utility knife blades between uses. Drywall rasps are not well suited for folding into and out of the handle of a typical combination tool. Foldable saws have been developed for pruning branches and such, but foldable keyholes saws are not well suited for combination with other tools that may be required by a carpenter. Additionally, all of the above described tools are subjected to considerable forces during normal usage. As a result, the handle must be configured for secure gripping across the palm of the hand of the user and must be sufficiently strong to withstand forces generated during day-to-day use. Furthermore, the tool desirably should be dimensioned for convenient storage, convenient access and safe covering of the sharp elements of the tool.
In view of the above, it is an object of the subject invention to provide a combination tool that can perform all or most of the functions that will be required by a person installing drywall.
It is an additional object of the subject invention to provide a tool that is safe in use, storage and access.
It is a further object of the subject invention to provide a combination tool that incorporates a razor sharp utility knife with blades that can be replaced easily.
Another object of the invention is to provide a combination tool with a keyhole saw that can be replaced if and when necessary.
Still a further object of the subject invention is to provide a combination tool with a rasp that can be replaced if and when necessary.